Tube mill



Oct. 28, 1930. w. JAEDEL was mm Filed April 19. 1929 Patented Oct. 28, 1930 UNITE SATE WILEELM J'AEDEL, OF COLOGNE-KALK, GERMANY, ASSIGNUR TO vHASCHINENBA.U-

.ANSTALT HUMBOLDT, F COLOGNE-HALE, GERMANY Turn MILL Application filed April 19, 1929, Serial No. 356,559, and in Germany April 23, 1928.

This invention relates to means for regulating the quantity of air and the velocity of the air in tube mills with internal sifting means, The invention consists more particularly in this, that the air introduced into the mill is divided, when entering, into two streams, one of which conveys the material to be ground into the mill and sifts it there and the other is conveyed directly into the delivery pipe. Through suitablydistributing these two streams of air, the sitting action of the mill may be regulated as desired.

- For carrying the idea underlying the invention into efi'ect a pipe is for instance rovided inside the mill, which is open at 0th ends, and which can be closed at one end by a throttle. The said pipe is mounted in the middle in such a manner that it has one end extending beyond the inlet branch for the material into the air inlet pipe and the other end opening into the outlet pipe for the material. Thus, by adjusting the throttle, the

strength of the stream of air, where it enters the mill, can be adapted to the Weight of the material to be broken up, so that material of less specific gravity Wlll also be deposited by the stream of air near the inlet end of the mill.

Preferably for this purpose mills of a known kind employing internal sifting will be used, which operate in such a manner that the comminuted material falls into pockets provided in the peripheral space surrounding the-tube mill, is raised by the said pockets and then falls through the slots in the pockets back into the peripheral space, the fine dust being conveyed away by the stream of air passing through the mill, while the coarser particles are subjected to further comminution.

The invention is illustrated in the accompanying drawing, in which Fig. 1 shows a sectional elevation of a tube mill accordin to the present invention on the line 1-1 0 Fig. 2, and Fig. 2 shows across section of the drum of the mill on the line 22 of Fig. 1, Fig. 3 is a cross section on the line 33' of Fi 1 and 2. In the tube mill a a nonper orated pipe I) is mounted axially, which is open at both ends and 15 provided at one end with a throttle a. The said pipe has one end extending into the a1r inlet pipe 03 beyond the branch 6, where the material enters. The other end of the pipe 6 is connected to the delivery pipe 7 for the material. Part of the stream of air entering at d can thus, according to the adjustment of the throttle c be conveyed through the pipe 6 directly to the delivery pipe f, While the other part of the stream of air, the strength of which 'is regulated by the throttle, conveys the material entering at e into the drum and delivers the fine dust which is held in suspension by pockets g provided with slots is or other suitable means beyond the delivery wall'k.

What I claim is:

Y 1. In a tube mill, the combination with a rotatable drum, having an inlet and an out let and containing loose grinding members, with means for introducing the material to be operated upon and for introducing a stream of air for withdrawing the ground material from the interior of the mill through the said outlet, of communicating means in open communication with the said outlet arranged inside the said drum and adapted to receive a portion of the stream of air introduced into the drum andto conduct it directly to said outlet, and adjustable controlling means inside said communicating means for regulating the flow of air through said communicating means so as to divide the in flowing air into two parts, with the flow of one of said parts adjustable relatively to the flow of the other, oneof said parts serving, V

for introducing the material to be treated into the mill and sitting it in the same, and the other of said parts proceeding directly to the outlet of the mill, as and for the purpose set forth.

2. In a tube mill, the combination witha rotatable drum, having an inlet and an outlet and containing loose grinding members, with means for introducing the material to be operated upon and for introducing a stream of air for withdrawing the ground material from the interior of the mill through the said outlet, of a pipe in open communication with the said outlet arranged inside the said drum and adapted to receive a portion of the stream of air introduced into the drum and to conduct it directly to said outlet, and ,a throttle valve inside said pi for regulating the flow of air through sai pipe so as to divide the infiowing air into two parts, with the flow of one of said parts adjustable relatively to the flow of the other, one of said parts serving for introducing the material to be treated into the mill and sifting it in the same, and the other of said parts proceeding directly to the outlet of the mill, as and for the. purpose set forth.

3. In a tube mill, the combination with a rotatable drum, having an inlet and an outlet and containing loose grinding members, with an air inlet pipe connected to said inlet for introducing a stream of air into the drum, means connected to said air inlet pipe for introducing thereto material to be operated on, a communicating pipe arranged inside said drum and extending into said air inlet pipe beyond the point of entry thereto of the material to be operated on, said pipe extending to the said outlet so as to be capable of establishing direct open communication between the air inlet pipe and the outlet for receiving a portion of air introduced into the air inletpipe and an adjustable throttle in said communicating pipe, as and for the purpose set forth.

4. In a tube mill, the combination with a rotatable drum, having an inlet and an outlet and containing loose grinding members, with means for introducing the material to be operated upon and for introducing a stream of air for withdrawing the ground material from the interior of the mill through the said outlet, of communicating means in open communication with the said outlet and adapted to receive a portion of the stream of air to be introduced nto the drum and to conduct it directly to said outlet, so as to divide the inflowing air into two parts, one of said parts serving for introducing the material to be treated into the mill and sifting it in the same, and the other of said parts proceeding directly to the outlet of the mill,

as and for the purpose set forth.

In testimony whereof I have signed my name to this specification.

WIL ELM JAEDEL. 

